text: /*
   * This file is part of the MicroPython project, http://micropython.org/
   *
   * The MIT License (MIT)
   *
   * Copyright (c) 2016 Scott Shawcroft
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  
  // This file contains all of the Python API definitions for the
  // bitbangio.I2C class.
  
  #include "shared-bindings/bitbangio/I2C.h"
  #include "shared-bindings/microcontroller/Pin.h"
  #include "shared-bindings/util.h"
  
  #include "lib/utils/buffer_helper.h"
  #include "lib/utils/context_manager_helpers.h"
  #include "py/mperrno.h"
  #include "py/runtime.h"
  #include "supervisor/shared/translate.h"
  
  //| class I2C:
  //|     """Two wire serial protocol"""
  //|
  //|     def __init__(self, scl: microcontroller.Pin, sda: microcontroller.Pin, *, frequency: int = 400000, timeout: int = 255) -> None:
  //|         """I2C is a two-wire protocol for communicating between devices.  At the
  //|         physical level it consists of 2 wires: SCL and SDA, the clock and data
  //|         lines respectively.
  //|
  //|         .. seealso:: Using this class directly requires careful lock management.
  //|             Instead, use :class:`~adafruit_bus_device.i2c_device.I2CDevice` to
  //|             manage locks.
  //|
  //|         .. seealso:: Using this class to directly read registers requires manual
  //|             bit unpacking. Instead, use an existing driver or make one with
  //|             :ref:`Register <register-module-reference>` data descriptors.
  //|
  //|         :param ~microcontroller.Pin scl: The clock pin
  //|         :param ~microcontroller.Pin sda: The data pin
  //|         :param int frequency: The clock frequency of the bus
  //|         :param int timeout: The maximum clock stretching timeout in microseconds"""
  //|         ...
  //|
  STATIC mp_obj_t bitbangio_i2c_make_new(const mp_obj_type_t *type, size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_scl, ARG_sda, ARG_frequency, ARG_timeout };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_scl, MP_ARG_REQUIRED | MP_ARG_OBJ },
          { MP_QSTR_sda, MP_ARG_REQUIRED | MP_ARG_OBJ },
          { MP_QSTR_frequency, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 400000} },
          { MP_QSTR_timeout, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 255} },
      };
      mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
      mp_arg_parse_all(n_args, pos_args, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
  
      const mcu_pin_obj_t *scl = validate_obj_is_free_pin(args[ARG_scl].u_obj);
      const mcu_pin_obj_t *sda = validate_obj_is_free_pin(args[ARG_sda].u_obj);
  
      bitbangio_i2c_obj_t *self = m_new_obj(bitbangio_i2c_obj_t);
      self->base.type = &bitbangio_i2c_type;
      shared_module_bitbangio_i2c_construct(self, scl, sda, args[ARG_frequency].u_int, args[ARG_timeout].u_int);
      return (mp_obj_t)self;
  }
  
  //|     def deinit(self) -> None:
  //|         """Releases control of the underlying hardware so other classes can use it."""
  //|         ...
  //|
  STATIC mp_obj_t bitbangio_i2c_obj_deinit(mp_obj_t self_in) {
      bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
      shared_module_bitbangio_i2c_deinit(self);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_deinit_obj, bitbangio_i2c_obj_deinit);
  
  STATIC void check_for_deinit(bitbangio_i2c_obj_t *self) {
      if (shared_module_bitbangio_i2c_deinited(self)) {
          raise_deinited_error();
      }
  }
  
  //|     def __enter__(self) -> I2C:
  //|         """No-op used in Context Managers."""
  //|         ...
  //|
  //  Provided by context manager helper.
  
  //|     def __exit__(self) -> None:
  //|         """Automatically deinitializes the hardware on context exit. See
  //|         :ref:`lifetime-and-contextmanagers` for more info."""
  //|         ...
  //|
  STATIC mp_obj_t bitbangio_i2c_obj___exit__(size_t n_args, const mp_obj_t *args) {
      (void)n_args;
      shared_module_bitbangio_i2c_deinit(args[0]);
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(bitbangio_i2c_obj___exit___obj, 4, 4, bitbangio_i2c_obj___exit__);
  
  static void check_lock(bitbangio_i2c_obj_t *self) {
      if (!shared_module_bitbangio_i2c_has_lock(self)) {
          mp_raise_RuntimeError(translate("Function requires lock"));
      }
  }
  
  //|     def scan(self) -> List[int]:
  //|         """Scan all I2C addresses between 0x08 and 0x77 inclusive and return a list of
  //|         those that respond.  A device responds if it pulls the SDA line low after
  //|         its address (including a read bit) is sent on the bus."""
  //|         ...
  //|
  STATIC mp_obj_t bitbangio_i2c_scan(mp_obj_t self_in) {
      bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
      check_for_deinit(self);
      check_lock(self);
      mp_obj_t list = mp_obj_new_list(0, NULL);
      // 7-bit addresses 0b0000xxx and 0b1111xxx are reserved
      for (int addr = 0x08; addr < 0x78; ++addr) {
          bool success = shared_module_bitbangio_i2c_probe(self, addr);
          if (success) {
              mp_obj_list_append(list, MP_OBJ_NEW_SMALL_INT(addr));
          }
      }
      return list;
  }
  MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_scan_obj, bitbangio_i2c_scan);
  
  //|     def try_lock(self) -> bool:
  //|         """Attempts to grab the I2C lock. Returns True on success."""
  //|         ...
  //|
  STATIC mp_obj_t bitbangio_i2c_obj_try_lock(mp_obj_t self_in) {
      bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
      check_for_deinit(self);
      return mp_obj_new_bool(shared_module_bitbangio_i2c_try_lock(self));
  }
  MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_try_lock_obj, bitbangio_i2c_obj_try_lock);
  
  //|     def unlock(self) -> None:
  //|         """Releases the I2C lock."""
  //|         ...
  //|
  STATIC mp_obj_t bitbangio_i2c_obj_unlock(mp_obj_t self_in) {
      bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(self_in);
      check_for_deinit(self);
      shared_module_bitbangio_i2c_unlock(self);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_1(bitbangio_i2c_unlock_obj, bitbangio_i2c_obj_unlock);
  
  //|     import sys
  //|     def readfrom_into(self, address: int, buffer: WriteableBuffer, *, start: int = 0, end: int = sys.maxsize) -> None:
  //|         """Read into ``buffer`` from the device selected by ``address``.
  //|         The number of bytes read will be the length of ``buffer``.
  //|         At least one byte must be read.
  //|
  //|         If ``start`` or ``end`` is provided, then the buffer will be sliced
  //|         as if ``buffer[start:end]``. This will not cause an allocation like
  //|         ``buf[start:end]`` will so it saves memory.
  //|
  //|         :param int address: 7-bit device address
  //|         :param WriteableBuffer buffer: buffer to write into
  //|         :param int start: Index to start writing at
  //|         :param int end: Index to write up to but not include"""
  //|         ...
  //|
  // Shared arg parsing for readfrom_into and writeto_then_readfrom.
  STATIC void readfrom(bitbangio_i2c_obj_t *self, mp_int_t address, mp_obj_t buffer, int32_t start, mp_int_t end) {
      mp_buffer_info_t bufinfo;
      mp_get_buffer_raise(buffer, &bufinfo, MP_BUFFER_WRITE);
  
      size_t length = bufinfo.len;
      normalize_buffer_bounds(&start, end, &length);
      if (length == 0) {
          mp_raise_ValueError(translate("Buffer must be at least length 1"));
      }
  
      uint8_t status = shared_module_bitbangio_i2c_read(self, address, ((uint8_t *)bufinfo.buf) + start, length);
      if (status != 0) {
          mp_raise_OSError(status);
      }
  }
  
  STATIC mp_obj_t bitbangio_i2c_readfrom_into(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_address, ARG_buffer, ARG_start, ARG_end };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_address,    MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_buffer,     MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_start,      MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_end,        MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
      };
      bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
      check_for_deinit(self);
      check_lock(self);
      mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
      mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
  
      readfrom(self, args[ARG_address].u_int, args[ARG_buffer].u_obj, args[ARG_start].u_int,
          args[ARG_end].u_int);
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_readfrom_into_obj, 1, bitbangio_i2c_readfrom_into);
  
  //|     import sys
  //|     def writeto(self, address: int, buffer: ReadableBuffer, *, start: int = 0, end: int = sys.maxsize) -> None:
  //|         """Write the bytes from ``buffer`` to the device selected by ``address`` and then transmits a
  //|         stop bit. Use `writeto_then_readfrom` when needing a write, no stop and repeated start
  //|         before a read.
  //|
  //|         If ``start`` or ``end`` is provided, then the buffer will be sliced
  //|         as if ``buffer[start:end]`` were passed, but without copying the data.
  //|         The number of bytes written will be the length of ``buffer[start:end]``.
  //|
  //|         Writing a buffer or slice of length zero is permitted, as it can be used
  //|         to poll for the existence of a device.
  //|
  //|         :param int address: 7-bit device address
  //|         :param ReadableBuffer buffer: buffer containing the bytes to write
  //|         :param int start: beginning of buffer slice
  //|         :param int end: end of buffer slice; if not specified, use ``len(buffer)``
  //|         """
  //|         ...
  //|
  // Shared arg parsing for writeto and writeto_then_readfrom.
  STATIC void writeto(bitbangio_i2c_obj_t *self, mp_int_t address, mp_obj_t buffer, int32_t start, mp_int_t end, bool stop) {
      // get the buffer to write the data from
      mp_buffer_info_t bufinfo;
      mp_get_buffer_raise(buffer, &bufinfo, MP_BUFFER_READ);
  
      size_t length = bufinfo.len;
      normalize_buffer_bounds(&start, end, &length);
  
      // do the transfer
      uint8_t status = shared_module_bitbangio_i2c_write(self, address,
          ((uint8_t *)bufinfo.buf) + start, length,
          stop);
      if (status != 0) {
          mp_raise_OSError(status);
      }
  }
  
  STATIC mp_obj_t bitbangio_i2c_writeto(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_address, ARG_buffer, ARG_start, ARG_end };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_address,    MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_buffer,     MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_start,      MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_end,        MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
      };
      bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
      check_for_deinit(self);
      check_lock(self);
      mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
      mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
  
      writeto(self, args[ARG_address].u_int, args[ARG_buffer].u_obj, args[ARG_start].u_int,
          args[ARG_end].u_int, true);
      return mp_const_none;
  }
  STATIC MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_writeto_obj, 1, bitbangio_i2c_writeto);
  
  
  //|     import sys
  //|     def writeto_then_readfrom(self, address: int, out_buffer: ReadableBuffer, in_buffer: ReadableBuffer, *, out_start: int = 0, out_end: int = sys.maxsize, in_start: int = 0, in_end: int = sys.maxsize) -> None:
  //|         """Write the bytes from ``out_buffer`` to the device selected by ``address``, generate no stop
  //|         bit, generate a repeated start and read into ``in_buffer``. ``out_buffer`` and
  //|         ``in_buffer`` can be the same buffer because they are used sequentially.
  //|
  //|         If ``out_start`` or ``out_end`` is provided, then the buffer will be sliced
  //|         as if ``out_buffer[out_start:out_end]`` were passed, but without copying the data.
  //|         The number of bytes written will be the length of ``out_buffer[start:end]``.
  //|
  //|         If ``in_start`` or ``in_end`` is provided, then the input buffer will be sliced
  //|         as if ``in_buffer[in_start:in_end]`` were passed,
  //|         The number of bytes read will be the length of ``out_buffer[in_start:in_end]``.
  
  //|         :param int address: 7-bit device address
  //|         :param ~_typing.ReadableBuffer out_buffer: buffer containing the bytes to write
  //|         :param ~_typing.WriteableBuffer in_buffer: buffer to write into
  //|         :param int out_start: beginning of ``out_buffer`` slice
  //|         :param int out_end: end of ``out_buffer`` slice; if not specified, use ``len(out_buffer)``
  //|         :param int in_start: beginning of ``in_buffer`` slice
  //|         :param int in_end: end of ``in_buffer slice``; if not specified, use ``len(in_buffer)``
  //|         """
  //|         ...
  //|
  STATIC mp_obj_t bitbangio_i2c_writeto_then_readfrom(size_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
      enum { ARG_address, ARG_out_buffer, ARG_in_buffer, ARG_out_start, ARG_out_end, ARG_in_start, ARG_in_end };
      static const mp_arg_t allowed_args[] = {
          { MP_QSTR_address,    MP_ARG_REQUIRED | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_out_buffer, MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_in_buffer,  MP_ARG_REQUIRED | MP_ARG_OBJ, {.u_obj = MP_OBJ_NULL} },
          { MP_QSTR_out_start,  MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_out_end,    MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
          { MP_QSTR_in_start,   MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
          { MP_QSTR_in_end,     MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = INT_MAX} },
      };
      bitbangio_i2c_obj_t *self = MP_OBJ_TO_PTR(pos_args[0]);
      check_for_deinit(self);
      check_lock(self);
      mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
      mp_arg_parse_all(n_args - 1, pos_args + 1, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
  
      writeto(self, args[ARG_address].u_int, args[ARG_out_buffer].u_obj, args[ARG_out_start].u_int,
          args[ARG_out_end].u_int, false);
      readfrom(self, args[ARG_address].u_int, args[ARG_in_buffer].u_obj, args[ARG_in_start].u_int,
          args[ARG_in_end].u_int);
  
      return mp_const_none;
  }
  MP_DEFINE_CONST_FUN_OBJ_KW(bitbangio_i2c_writeto_then_readfrom_obj, 1, bitbangio_i2c_writeto_then_readfrom);
  
  STATIC const mp_rom_map_elem_t bitbangio_i2c_locals_dict_table[] = {
      { MP_ROM_QSTR(MP_QSTR_deinit), MP_ROM_PTR(&bitbangio_i2c_deinit_obj) },
      { MP_ROM_QSTR(MP_QSTR___enter__), MP_ROM_PTR(&default___enter___obj) },
      { MP_ROM_QSTR(MP_QSTR___exit__), MP_ROM_PTR(&bitbangio_i2c_obj___exit___obj) },
      { MP_ROM_QSTR(MP_QSTR_scan), MP_ROM_PTR(&bitbangio_i2c_scan_obj) },
  
      { MP_ROM_QSTR(MP_QSTR_try_lock), MP_ROM_PTR(&bitbangio_i2c_try_lock_obj) },
      { MP_ROM_QSTR(MP_QSTR_unlock), MP_ROM_PTR(&bitbangio_i2c_unlock_obj) },
  
      { MP_ROM_QSTR(MP_QSTR_writeto), MP_ROM_PTR(&bitbangio_i2c_writeto_obj) },
      { MP_ROM_QSTR(MP_QSTR_readfrom_into), MP_ROM_PTR(&bitbangio_i2c_readfrom_into_obj) },
      { MP_ROM_QSTR(MP_QSTR_writeto_then_readfrom), MP_ROM_PTR(&bitbangio_i2c_writeto_then_readfrom_obj) },
  };
  
  STATIC MP_DEFINE_CONST_DICT(bitbangio_i2c_locals_dict, bitbangio_i2c_locals_dict_table);
  
  const mp_obj_type_t bitbangio_i2c_type = {
      { &mp_type_type },
      .name = MP_QSTR_I2C,
      .make_new = bitbangio_i2c_make_new,
      .locals_dict = (mp_obj_dict_t *)&bitbangio_i2c_locals_dict,
  };
  